Driven by advances in electronic miniaturization, probe construction techniques and computing power, medical ultrasound is experiencing a trend toward smaller, lower cost systems with real-time volumetric imaging capabilities. These new attributes provide the opportunity to improve and expand the clinical utility of ultrasound to new applications. The combination of miniaturization and new attributes permits the expansion to previously underserved populations. Cardiovascular parameters for screening and monitoring, such as in a bedside or ambulatory setting, is one of these untapped areas that can benefit from quantitative, non-invasive measurements. Continuous and accurate measures of arterial parameters will provide additional information for earlier detection and more effective treatment of diseases, such as atherosclerosis and hypertension, while the clinical utility of any new measure will ultimately be determine by the reliability. Preliminary studies on in vitro and in vivo models have shown the potential of ultrasound hemodynamic measures in a laboratory setting. The proposal aims to develop and validate quantitative hemodynamic measures for new cardiovascular applications on next generation volumetric ultrasound systems. The technical development specifically focuses on reliable measurement algorithms for (1) quantitative arterial area and volumetric flow rate, (2) arterial compliance, and (3) continuous blood pressure. The approach utilizes volumetric ultrasound to provide structural information allowing typical qualitative ultrasound measures to be converted into quantitative measures. By combining volumetric ultrasound with automatic methods to locate the vessel and continuously process the data, the reliability and ease of use can be improved to the point where a sonographer is not required. A simplified 3-D architecture developed from existing hardware will be modified for these feasibility studies, and the ultrasound-based quantitative hemodynamic measures will be validated and the measurement variation quantified using invasive flow and pressure sensors under a variety of physiological conditions during acute and chronic studies in anesthetized and conscious canine models.